Electrical apparatus



Patented Aug. 2, 1932 UNITED STATES PATENT OFFICE omo, assronons 'roDELOO- a conrona'rron or DELAWARE ELECTRICAL APPARATUS Application filedAugust 30, 1929. Serial No. 889,488.

This invention relates to electrical generating systems of the typewhich include preferably an internal combustion engine, a storagebattery, a work circuit and electrical apparatus operated by the enginefor sup lying current to the storage battery and to the work circuit;and more particularly to the automatic control for such systems.

One of the objects of the present invention is to provide im roved meansfor controlling the operation 0? the electrical apparatus to thusmaintain a substantially constant voltage output therefrom. Inelectrical generating systems employing an internal combustion enginefor driving a-generator, a voltage coil responsive to the voltage of thegenerator is used for controlling a throttle valve for the engine tothus control the speed of the engine and consequentl the voltage of thegenerator. Voltage coi s of this type gradually vary in effectiveness asthey gradually become heated by current flow therein and therefore thevoltage of the generator when starting will be different than afterthe-system has been in o eration for some time. 7 It is a more specii icobject of the present invention to compensate for this change ineffectiveness of the voltage coil whereby the volta e of the generatoris maintain'edsubstantially constant at all times.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being bad to the accompan ingdrawing ferred form of the present invention is clearly shown.

In the drawing:

The figure of the drawing is a wiring dia gram illustrating the presentinvention.

In the drawing, designates, a prime mover herein shown, for the purposeof illustration, as an internal combustion engine having a shaft 21which drives a relatively high voltage generator 22 having main brushes23 and 24 connected with the armature of the generator, and having ashunt field winding 26. i

The engine is started by a relatively low voltage series motor 27 whichis normally disconnected from the engine, but may be wherein a pconnected automatically withthe engine for cranking the latter whenevercurrent is supplied to the motor; and which is automaticallydisconnected from the engine when the engine becomes self-operative. Asvarious devices for connecting and disconnecting the I starting motorare well known to those skilled in the art, illustration thereof isdeemed unnecessary. One form of mechanical connection which may be usedfor this invention is described'and claimed in the co-pendingapplication of Frank F. Starr, Serial N 0. 47,717, filed April 3,1925.

The ignition apparatus comprises an ignition coil primary 30, anignition timer 31 and 06 an ignition .coil secondary 32 whichisconnected with an engine. spark plug 33.

A throttle 35 for regulating the speed of the engine is adapted to beactuated by a throttle control 37. To

To start the engine automatically in response to a demand for current bya translating device 39 contained in the work circuit 40, one of theswitches 42 is closed, thereby causing current to flow from a storagebattery 7:, 45 through the following circuit: battery 45, wire 46,contact 48, contact 49, resistance 50, wire 51, wire 53, series winding54 of throttle control \37 wire 55, service main 56, switch 42,translating device 39, service main 57, 80 wire 58, magnet coil 59,magnet coil 60, wire 61, and wire 62 to the other side of the battery.Coil 60 is of relatively high resistance and therefore limits the flowof current from the battery to the work device. The energizing of coils59 and 60 which form a part of starting switch relay 65 causes anarmature 66 to be drawn upwardly to connect a movable contact 67 with astationary contact 68.

When contacts 67 and 68 are closed, current 00 will flow from thebattery through the magnet 69 of a starting switch 7 O which includes aplunger 71 'which, when moved upwardly, will cause a contact72, which ispivoted at 73, to engage a contact 74. The circuit betweenthe batteryand the magnet 69 is as follows: battery'45, wire 46, contacts 67 and68, wire 76, wire 77, contacts 78 andv 79, wire 80, magnet 69, wire 81,contacts 82 and 83, Wire 84, and wire 62 to the other side of the spring93 is restrained by of the dynamo 22 battery. The closing of contacts 67will connect the ignition coil primar 30 with the storage battery throuh the ollowing circuit: wire 46, contacts 67 and 68, wire 7 6, timer 31,primary 30, wire 90,'wire 81, contacts 82 and 83, wires 84 and 62 to theother side of the battery. Thus, the engine will be started by supplyingi ition thereto. an cranking the engine by t e starting motor 27.

If the engine should not start within a certain length oftime, abnormaldischarge of the battery is prevented by a cranking cut-out 92 whichincludes the contacts 82 and 83. The contact 82 is attached-to a lever93 which is pivoted at 94 and is urged upwardly by a 95. Upward movementof the lever the engagement of a nonconducting block 97 attached to thelever 93 with the lower end of a bimetallic thermostatic blade 98 fixedat 99. The blade 98 is in heat receiving relation to a heating coil 100which isconnected across the battery terminals by connecting one end ofthe coil 100 with the wire 86, and the other end with a wire 87. If thecranking of the engine should continue for an abnormal period, thebimetallic blade 98 will be heated sufiiciently to cause it to bowtoward the left, as viewed in until the lower end of the blade 98 movesas't the shoulder 101 of the non-conducting lock 97. When this occurs,the lever 93 will move upwardly and separate the contact 82from thecontact 83. This operation will thus disconnect the coil 69 from thebattery 45, so that the plunger 71 will descend by gravity to movethecontact 72 away from the contact 74. Thus the starting circuit will beinterrupted.

During normal operation,

and 68 the drawing,

when the prime mover 20 becomes self-operative and the generator hasattained a relatively hi h voltage, a load switch 105 will automatica 1yconnect the dynamo 22 with the work circuit 40. The switch 105 includesa magnet coil 106 havin its ends connected across the dynamo 22. en thevoltage across the brushes exceeds-a certain amount a plunger 107 of theload switch 105 will be actuated in order to move the contacts 109 and110 into engagement. Before contact 109 engages contact 110a contact 111will first en a e a contact 112. This feature is provi e to insureclosing of the battery charging circuit before the work circuit is closeThe engine cranking circuit is interrupted after the engine becomesself-operative, by a stop cranking relay 115 which includes contacts 78and 79, a magnet winding 117 connected across the dynamo and amagnetizable plunger 118 having lost motion connection 119 with acontact 78 which is pivoted at 120. When the dynamo voltage reaches acertain relatively low'value, the magnet coil 117 will be sufiicientlyenergized to actuate the plunger 118 in order to separate the contact 78trol 37, wire winding.

from the contact 79. When this occurs the circuit between the battery 45and the magnet winding 69 of the starting switch will be interrupted,thereby permitting the plunger 71 to descend and the contact 72 to beseparated from the contact 74. After the plunger 118 has been movedsufficiently by the magd net 117 to separate the contact 78 from thecontact 79, the plunger 118 will be maintained in this position, thespeed of the engine and the corresponding voltage of the dynamo willfall materially below the speed and voltage producing the separation ofthe contacts 78 and 79. Thus, the possibility of reconnecting thestarting circuit after the prime mover is self-operative has beeneliminated, although the engine speed might become comparatively low.

During normal operation the dynamo 22 functions to supply current to thetranslatin device 39 contained in thework circuit 40 an suppliescharging current to the battery 45. The flow of current from the dynamothrough the work circuit is as follows: brush 23 of dynamo 22, wire 53,series winding 54 of con- 55, service main 56, switch 42, translatingdevice 39, wire 58, magnet coil 59 of relay 65, wire 123, contacts 110and 109 and wire 124 to the other side of the dynamo. The flow ofcurrent from the dynamo 22 through the battery follows: brush 23 ofdynamo 22, wire 51, resistance 50, switch contacts-49 and 48, wire 46,the relatively low voltage storage battery 45. wire 62, wire 126,contacts 112 and 111 and wire 124 to the other side of the dynamo.

The throttle I control 37 also includes a shunt winding 130, athermostatic element 131 and a plunger 133 which is'operativelyconnected with the throttle 35 and a bi-metallic thermostatic blade 135of the thermostatic element 131. The blade 135 forms a resilient supportfor plunger 133 and is adapted to hold the same in position when thewindings 54 and 130 are deenergized. During operation of the system theseries windin 54 and the shunt windin 130 are adapte to oppose oneanother, t e series winding 54 tending to move the plunger 133.downwardly to open the throttle, increasing its effectiveness as theload increases, while the shunt winding 130 tends to move the plunger133 upwardly to close the throttle.

11 actual practice the. shunt windin wound inside the series winding54', ut for the purpose of a clear illustration the windings have beenshown one above the other.

After the shunt winding 130 becomes energized, the winding is' adaptedto heat gradually, due to the flow of current therethrough, to thuscause the resistance thereof to increase thereby varying theeffectiveness of this In order to overcome this disadvantage thethermostatic element 131 has charging circuit is as' been provided. Thedevice 131 includes the bi-metallic thermostatic blade 135 which isfixed at 137. This blade is adapted to be heated or cooled and therebymoved to compensate for the change in the voltage coil 130. In thepresent case, the arrangement is such that thermostat is heated for suchcompensation and preferably this heating is accomplished by heating coil138. The blade 135 is 1n heat receiving relation to the coil 138, andafter a certain length of time the blade 135 will be heated sufficientlyto cause it to bow upwardly to thus compensate for the variation ineffectiveness of the shunt windin 130. In this manner the voltage output0 the dynamo 22. is maintained substantially constant at all times. Thecircuit from the dynamo 22 through the shunt winding 130 and through thelows: brush 23 of dynamo 22, .wire 53, wire 140 to connecting point 141where the current divides; part flowing-through wire 143, shunt winding130 and wire 144 to the other side of the dynamo; the other part of thecurrent flowing from connecting point 141 through heating coil 138 andwire 144 to the other side of the dynamo.

Magnet coils 59 and 60, contacts 67 and 68 are included in theinstrument 65 which serves to efiect the operation of the startingapparatus and to close the ignition circuit and to maintain it closeduntil the current demand in the work circuit ceases, and to interruptthe flow of current to the batter when the current demand in the workcircuit exceeds a certain amount. 7 y

The instrument or relay 65 comprises a ma-gnetizable angle 150 attachedto a core 151 located within the windings 59 and 60. The angle 150supports the armature 66 by a flexible metallic hlnge 153'. The contact67 is carried by a flexible metallic conductor 154 attached to thearmature 66. The contact 48 is carried by a flexible, magnetizablemetallic member 155 connected with the angle 150 by a non-magnetizableblock 157. When the current flowing throu h coil 59, which is in thework circuit, exceeds a certain amount the magnetic path provided by themembers 151, 150 and 66 will be saturated and some of the flux willstray into the region of the I magnetizable member 155 to cause the sameto be drawn toward the an le 150 to separate contacts 48 and-49. In thisway the battery charging circuit is interrupted when the demand forcurrent in the work circuit exceeds I a certain amount.

From the foregoing description, it is ap parent that we have provided adevice for controlling the operation of the generating system, and havearranged for compensating the variation in effectiveness of such device.

By this arrangement there is insured a sub- I stantially constantvoltage output by the dynamo.

heating coil 138 is asfolby said voltage coi While the form ofembodiment of the invention as herein disclosed constitutes a preferredform, it is to be understood that other forms might be adopted, allcoming within the scope of the claims which follow.

What is claimed is as follows:

1. An electrical generatin system comprising in combination a worcircuit, electrical apparatus, a prime mover for driving the electricalapparatus, said electricalapparatus beingadapted to supply current tosaid circuit, a throttle valve on the rims mover for controlling theoutput of t e electrical apparatus, a coil for actuating said valve,

said coil being adapted when energized for a predetermined length oftime to vary in effectiveness, a voltage coil energized by theelectrical apparatus and a thermostat heated l and mechanicallyconnected to said means for compenspting such variation inefiectivenessof said coil.

v2; An electrical generating system comprising in combination a workcircuit, electrical apparatus, a prime mover for driving the electricalapparatus, said electrical apparatus being adapted to supply current tosaid circuit, a throttle valve on the rime mover -for controlling theoutput of t e electrical apparatus, a shunt coil connected across theelectrical apparatus, awinding connected in series with said workcircuit, said coil and said winding being-adapted to actuate said valve,saidcoil being adapted when energized for a predetermined len h of timeto vary ineffectiveness, and an e ectrically operated thermostat heatedby said voltage coil and mechanically connected to said means forcompensating such variation in effectiveness of said coil.

3. An electrical generatin system comprising in combination a worcircuit, el ectrical apparatus, a prime mover for drlvmg the electricalap aratus, said electrical apparatus being a apted to supply current to'said circuit, a throttle valve on the prime mover for controlling theoutput of the electrical ap aratus, a coil' for actuating said valve,saldcoil being ads. ted when energized for a predetermined ength of timeto vary in effectiveness, and electrically operated means forcompensating" such variation of effectiveness of said coil, said meansincluding a voltage coil energized by the electrical apparatus. v. 4. Anelectrical generating system comprising in combination a work circuit,electr1cal apparatus, a prime mover-for driving the e ectricalapparatus, said electrical apparatus being a circuit, a throttle valveon the rime mover for controllin the output of t 0 electrical apted tosupply current to said apparatus, a s unt coil connected across the eectrical apparatus, a. winding connected in series with said workcircuit, said coil and said winding being adapted to actuate Band valve,said coil being adapted when energized for a predetermined length oftime to vary in effectiveness, and electrically operated means forcompensating such variation of efiectiveness of said coil, said meansinclud- 6 ing a voltage coil energized by the'eleotrical ap aratus. a

n testimony whereof we hereto afiix our signatures. WILLIAM C. WELLS. l0WESLEY E. WENDT.

